This invention pertains to aminomethyl phenol derivatives for cross-linking active hydrogen containing resins and to a process for low-temperature heat curing such resins.
In the past, resinous coating compositions containing active hydrogens have been cured or cross-linked with low molecular weight resins or oligomers such as aminoplast resins, phenoplast resins, or resins containing oxirane or isocyanate groups as the cross-linking group.
It now has been found that active hydrogen containing resins can be efficiently cross-linked by heat curing in the presence of an aminomethyl phenol derivative to produce substantially improved cross-linked coatings exhibiting excellent chemical resistance along with other desirable film physical integrity properties. The phenol cross-linking derivative can be phenols, phenolic compounds or phenolic resins containing at least two methylene amine groups in conjugated positions relative to the phenol group or aromatic alcohol functional group on an aromatic ring based alcohol. When the aminomethyl substituted six membered aromatic rings contain a hydroxyl in the 2, 4, or 6 position in combination with two conjugated aminomethyl groups, the reactivity of the aminomethyl functionality to nucleophilic substitution is substantially increased to provide a remarkably active cross-linking mechanism for cross-linking resin coating compositions containing active hydrogens.